This is an amended application to develop and preliminarily test a psychosocial intervention designed to reduce HIV sexual risk behavior among men who have sex with men (MSM) who have a history of childhood sexual abuse (CSA). Evidence suggests that MSM report higher levels of childhood sexual abuse than men who do not have sex with men, and that childhood sexual abuse is associated with increased sexual risk for HIV. This intervention application is consistent with research suggesting that high risk behavior among MSM are one aspect of an overall set of syndemics (Stall et al, 2003) of psychosocial problems among this population. The proposed intervention will incorporate both state-of-the-art intervention approaches for reduced sexual risk taking with Cognitive-Processing Therapy for post-traumatic stress symptoms related to CSA. The intervention development approach will follow a staged model consistent with NIH guidelines for developing and standardizing behavioral therapies (Rounsaville et al., 2001). During the first year, startup activities will include piloting the intervention on a subset of up to 10 individuals, soliciting internal, expert consultant, and participant feedback, and development of the final treatment manual. The goal during this phase will be to establish feasibility, acceptability, and potential for an effect. During the following 2 years an initial two-arm efficacy study will be undertaken. The two arms of the randomized controlled trial will be 1) the experimental condition (Cognitive-Processing Therapy for CSA integrated with HIV risk reduction counseling), and 2) the control condition (HIV risk reduction counseling alone). Participants (n = 40 completers) will be MSM who report a history of childhood sexual abuse and at least three HIV sexual risk-taking episodes over the past 6 months (unprotected anal intercourse). The primary outcome will be self-reported sexual risk taking. Secondary outcomes will be reductions in negative effects of trauma and exploration of putative mediators. The innovativeness of the project lies in its attempt to use a holistic approach to HIV prevention among MSM, by addressing an important mental health variable integrated with risk reduction counseling. The proposed project will merge expertise and infrastructure for HIV prevention research among MSM from Fenway Community Health with expertise in psychosocial treatments for post-traumatic stress from the Department of Psychiatry at Massachusetts General Hospital and Boston University.